Yes, Jitsi can stream to YouTube. 

As for live streaming within UNA site - it is possible in concept, but certainly not something a startup-site can shoulder. One-to-many broadcasts can’t be handled with WebRTC alone. You have to setup a RTMS of some kind to direct steams. It’s resource intensive and even a mildly viral broadcast (1000+ viewers)  will call for a clustered setup running the media server. Jitsi has some plugins to make it possible but it’s not straightforward- say you can use Jibri, which creates virtual chrome instance and records/encodes with ffmpeg. only one instance can run in one virual machine... all in all it’s a complicated setup, which we can implement for custom projects, but would be far too complicated for out of the box installations. At least for now. 

Also, consider other tooling necessary for live video streaming - you HAVE to have continious monitoring by human admins. These tools are commonly infested by flashers, porn, copyright infringements, spammers, hate videos, violence broadcast, etc. Going there unprepared is not recommended. 

So, you have to have beefy hardware, robust admin team, solid policies and strong legal protections before even launching live streaming. And even then, it would only work better than recorded Videos if your community is large and active.